1. Field of the Invention
Embodiments of the invention are related to analysis of individual or simultaneously transmitted data streams containing data packets.
2. Background of the Art
In communication networks, especially in Voice Over IP communication networks, the RTP (Real Time Protocol) is often used to transmit data streams or multimedia data streams consisting of data packets, i.e., user information or speech information. The RTP is defined in RFC standard 1889, or since 2003 in RFC standard 3550. Due to increased security requirements, data streams have been transmitted encrypted for quite some time, and the secure RTP used for this is described in RFC standard 3711. In this context, the key information required for encryption is assigned and used on a data-stream-specific basis. As an example, for a multimedia session between two endpoints on an IP-based communication network, an audio and a video data stream are each transmitted in one transmission direction. Related to both transmission directions, four data streams are transmitted within a multimedia session, each of which is encrypted separately, i.e., encrypted data-stream-specifically. The key information for that particular session or data stream is assigned or processed during connection signaling—using the SIP (Session Initiation Protocol), for example—with a special key used to encrypt the connection signaling—Preshared Secrets, for example—which cannot be recognized even if the data stream is hacked.
In communication networks, multiple data streams or multimedia data streams are generally transmitted through a transmission leg or transmission segment. For problem situations arising in communication networks, analysis or diagnosis of the transmitted data streams is necessary in order to locate or delimit errors. For error analysis or diagnosis, reconstruction of the unencrypted data streams is usually necessary. An analysis or diagnosis is often performed on transmission segments with multiple data streams transmitted simultaneously using the RTP, so that the key information in the data streams (RTP data streams, for example), is not available and cannot be determined even during connection signaling, because the signaling information and the key information are re-encrypted, and the key information used is not available.